11.5. Native OS Device Driver Thermal Interfaces¶
OS implementations compatible with the ACPI 3.0 thermal model, interface with the thermal objects of a thermal zone but also comprehend the thermal zone devices’ OS native device driver interfaces that perform similar functions to the thermal objects at the device level.
The recommended native OS device driver thermal interfaces that enable OSPM to perform optimal performance / thermal management include:
Reading a value from a device’s embedded thermal sensor
Reading a value that indicates whether temperature and trip point values are reported in absolute or relative temperatures
Setting the platform’s cooling mode policy setting
Reading the embedded thermal sensor’s threshold
Reading the device’s active and passive cooling temperature trip points
Reading the device’s association to a thermal zone
Signaling the crossing of a thermal trip point
Reading the desired polling frequency at which to check the devices temperature if the device cannot signal OSPM or signal OSPM optimally (both before and after a temperature trip point is crossed)
Setting / limiting a device’s performance / throttling states
Engaging / disengaging a device’s active cooling controls
These interfaces are OS specific and as such the OS vendor defines the exact interface definition for each target operating system.